What is SLS – Sodium Lauryl Sulfate?

On average women add more than 200 chemicals to their skin daily, and more than 60% of these chemicals get absorbed directly into the bloodstream. Combine this with chemicals found in hair care and dental

Sodium Lauryl Sulfate
On average women add more than 200 chemicals to their skin daily, and more than 60% of these chemicals get absorbed directly into the bloodstream. Combine this with chemicals found in hair care and dental hygiene products, such as Sodium Lauryl Sulfate and Sodium Laureth Sulfate, and it’s no wonder why more people are searching for a natural solution.


There are a lot of rumors out there about Sodium Lauryl/Laureth Sulfate. Is it really a carcinogen? What about an endocrine disruptor and skin irritant? What’s truth and what’s myth? We’ve put together this article to clear up the confusion about the debated chemical. There’s no need to spread lies…the truth is scary enough. To make it easy we’re going to refer to Sodium Lauryl Sulfate and its even more evil twin, Sodium Laureth Sulfate from this point forward as SLS.

If you have the suspicion that washing your face is making your skin dry, or that shampooing is giving you an itchy scalp or making your eyes sting, or that cleaning your teeth is giving you mouth ulcers, sodium lauryl sulfate is the likely culprit. In studies, there are “significant correlations” (in the words of one) between SLS and contact dermatitis. The Journal of the American College of Toxicology says that it has “a degenerative effect on the cell membranes because of its protein denaturing properties”. The Journal adds that “high levels of skin penetration may occur at even low use concentration.


10 Reasons to avoid SLS – Sodium Lauryl Sulfate

1. It is a known skin irritant. When cosmetic companies need to test the healing properties of a lotion, they need to irritate the skin first. What do they use to do this? SLS, of course. If you have dandruff, dermatitis, canker sores, or other irritated tissues or skin, it could be due to SLS.

2. It pollutes our groundwater. It is toxic to fish and other aquatic animals and has the potential for bioaccumulation (meaning it accumulates in the bodies of the fish.) It also is undetected in many municipal water filters, getting into the tap water that you drink.

3. It is actually a pesticide and herbicide. It is commonly used to kill plants and insects. Makers of SLS recently petitioned to have SLS listed as an approved pesticide for organic farming. The application was denied because of its polluting properties and environmental damage.

4. It emits toxic fumes when heated. Toxic Sodium Oxides and Sulfur Oxides are released when SLS is heated. Makes a hot shower with an SLS shampoo seem not quite as nice…

5. It has corrosive properties. According to the American College of Toxicity, this includes corrosion of the fats and protiens that make up skin and muscle. SLS can be found in garage floor cleanrs, engine degreasers, and car wash soaps.

6. Long-term permeation of the body’s tissues. A study from the University of Georgia Medicine showed that SLS had the power to permeate the eyes, brain, heart, and liver.

7. It’s an eye irritant. It was shown to cause cataracts in adults, and is proven to inhibit the proper formation of eyes in small children.

8. Nitrate and other solvent contamination. Toxic solvents, including carcinogenic nitrates are used in the manufacturing of SLS, traces of which can remain in the product.

9. Manufacturing process is highly polluting, emitting cancer-causing volatile organic compounds, sulfur compounds, and air particulates.

10. It helps other chemicals get into your body. SLS is a penetration enhancer, meaning that its molecules are so small they’re able to cross the membranes of your body’s cells. Once cells are compromised, they become more vulnerable to other toxic chemicals that may be with the SLS.


Can SLS – Sodium Lauryl Sulfate cause Cancer?

At this point in time there is no scientific evidence that links the use of SLS to Cancer.

Sodium laureth sulfate and sodium lauryl sulfate are not known carcinogens, according to the American Cancer Society. However, some studies show the harsher sodium lauryl sulfate may cause mutations that could lead to cancer, notes Columbia University’s Health Services advice column “Go Ask Alice!” However, the evidence isn’t clear whether the small amounts used in shampoos and other personal products would be enough to cause cancer.


Which products contain SLS – Sodium Lauryl Sulfate

SLS is a common ingredient in laundry detergents, dish soaps, shampoos and toothpaste. It can be found in products sold under popular brands like Tide, Pantene and Colgate. It is also in cleaners made by companies in the natural-products space, including Seventh Generation laundry detergent, Method dish soap and Tom’s of Maine toothpaste. SLS is also in the coatings of some drugs to help them dissolve after being swallowed.


What do consumer products makers say about SLS – Sodium Lauryl Sulfate

“For many years, SLS was the star surfactant in skincare products, despite being a known irritant. … We’ve switched over to sodium coco sulfate, which is a gentler alternative always derived from coconut.” — The Honest Company

“We use SLS only at the levels needed to deliver on its intended purpose, delight consumers and be safe. It also has no known toxicity–not even when ingested.” — Tom’s of Maine

“Due to its concentrated chemistry, SLS has become the benchmark for irritation studies.” – EO Products

“SLS is a widely used surfactant in cleaning products, cosmetic, and personal care products. SLS’s uses in these products have been thoroughly evaluated and determined to be safe for consumers and the environment.” — Procter & Gamble


4 thoughts on “What is SLS – Sodium Lauryl Sulfate?

  1. Wow. I really loved this article! I have bookmarked it to read again. I have also tried to stay away from commercial shampoos and toothpastes (esp those containing flouride), but now i have become a bit lazy. I have tried brushing with coconut oil, but did not carry on with it. I would still love to try making my own castille soap shampoo. I am also a homeschooling mama of 3 : ) Please keep in touch!

    1. Thank you! Yeah, we try to stay away from artificial ingredients and hazardous chemicals as much as possible. Fluoride/chemical free toothpaste is a big one. I’ll be sharing a DIY toothpaste soon, keep an eye out 🙂

  2. I switched to SLS free shampoos & conditioners years ago, but I had not heard that it was in laundry soap! We use Seventh Generation, too. 🙁 I’ll have to switch back to Honest Company.

Leave a Reply

Your email address will not be published. Required fields are marked *